Minor Civilization Status

Playing with "Start as Minors" and Barbarian Civs, I now have a strange situation: all the Barb Civs that spawned in the "new world", as the BUG options see it (landmasses separated by Ocean from the landmass(es) where the starting civs spawned) are still tagged as "Minors", even though they are way beyond the discovery of Writing (which normally is when a "minor" civ becomes "full"). Some have even founded their own religion! (I'm also playing with Limited Religions)
I understand that this originates from my own specific BUG options, where I selected that "New World Barb Civs" can grown into full civs only after a unit of an "old world" civ has landed on their landmass.
However I've already sent a couple Explorers over there (which have been quickly killed by the locals), yet they all are still "minors".

Case Study: the Venetians.
One of the first "new world" barb civs that my Caravels discovered, I've landed an Explorer there, their Crossbows killed it two turns later, yet they stay minors.
They even founded Asatru, meaning they are not so behind technologically!


My question is: is there a way, through WorldBuilder or by editing the savegame, to remove the "minor" status from civilizations?
I am aware that I could save the game as a scenario through WB, then edit the file with a text editor and remove said minor status from the civ list. The problem however is that this procedure also eliminates any information about the original founding civs of conquered cities (the Assimilation option), which is an important part of the story I'm writing about this game.

Alternatively, is there a way to save scenarios and maintain said information about conquered cities?

Ohh, that's an issue I have often seen in my games ("Than why didn't you report it?!" - they shout). My theory is that some minors just "avoid" Writing tech. I think it is possible that when a barb city becomes a minor cir civ the Barbarian State already knows a lot of techs, it inherits them to the new civ, which is on a level of research that he doesn't need Writing for any newer techs.

Could you check in WB if your minors have Writing or not? If not, than gifting them the tech via WB may solve your problem.